Power brake Q.
Thread Starter
|
Cargo Master
Joined: Apr 2003
Posts: 2,408
Likes: 5
From: Parkesburg PA
Power brake Q.
I am working on an 83 F100 and I have a problem with the brakes. The truck had been sitting for about 2 years before I got it. The first time that I drove it the brake pedal was rock hard and it didn't stop well at all. It got a little better the more I drove it.
I have so far checked the rears, replaced the front pads and one caliper. The brakes are better, and the pedal is softer but it still doesn't feel right. One thing that I noticed is that, with your foot on the brakes, when you shut the truck off the pedal pushes back at you. I'm going down to work on it some more tomarrow and I'd appreciate any hints on what to look for.
I have so far checked the rears, replaced the front pads and one caliper. The brakes are better, and the pedal is softer but it still doesn't feel right. One thing that I noticed is that, with your foot on the brakes, when you shut the truck off the pedal pushes back at you. I'm going down to work on it some more tomarrow and I'd appreciate any hints on what to look for.
New User
Joined: May 2003
Posts: 20
Likes: 0
Power brake Q.
Stop the truck and turn it off, without touching the brakes. After it stops running, hit the brakes a couple times. If the pedal is much easier to push the first time than the rest, the booster is doing it's job - but might still be leaking air.
also, with the truck running and your foot OFF the brake, listen for a hissing sound, which goes away when you hit the brake. That will indicate a leak in the diaphragm on the booster.
The truck was sitting for 2 years? I would replace BOTH calipers, and make sure to bleed them thoroughly and properly, doing the passenger side first.
Causes of hard pedal are improperly bled brakes, locked calipers, or a bad booster. Has the master cylinder been changed recently, and was it proper bench bled?
If you bench bleed the master cylinder, then replace the other caliper and bleed the whole thing (rr/lr/rf/lf) I'm willing to bet your problem will go away. If that doesn't do it, change your power booster.
also, with the truck running and your foot OFF the brake, listen for a hissing sound, which goes away when you hit the brake. That will indicate a leak in the diaphragm on the booster.
The truck was sitting for 2 years? I would replace BOTH calipers, and make sure to bleed them thoroughly and properly, doing the passenger side first.
Causes of hard pedal are improperly bled brakes, locked calipers, or a bad booster. Has the master cylinder been changed recently, and was it proper bench bled?
If you bench bleed the master cylinder, then replace the other caliper and bleed the whole thing (rr/lr/rf/lf) I'm willing to bet your problem will go away. If that doesn't do it, change your power booster.
Moderator
Joined: Jan 2001
Posts: 56,983
Likes: 2,736
From: Virginia
Power brake Q.
I agree with lectrick. I would replace both calipers, pads and redo the rear wheel cylinders. These parts are not expensive. The only thing that may be aggravating is the brake lines being rusty and twisting in two. Don't worry, you can get the universal lines to fit what gets broken. This may not fix your booster problem, but will guarentee everything else will be working properly.
